AlTiC和Al4B、Al3Ti4B中间合金对纯铝和亚共晶铝硅合金的细化机理

研究了ＡＩＴｉＣ和ＡＩ４Ｂ、ＡＩ３Ｔｉ４Ｂ等中间合金细化剂对纯铝和亚共晶铝硅合金的细化效果和细化机理。实现发现ＡＩ６Ｔｉ０．２Ｃ对纯铝有很好的细化效果，但对高Ｓｉ含量的亚共晶铝硅合金几乎没有细化效果；而ＡＩ４Ｂ、ＡＩ３Ｔｉ４Ｂ等ｗ（Ｔｉ）／ｗ（Ｂ）〈２．２（ｗ（Ｔｉ）／ｗ（Ｂ）＝０时即为ＡＩ－Ｂ合金）的ＡＩＴｉＢ合金对纯铝没有细化效果，但对亚共晶铝硅合金却有非常好的细化效果。上述实验结果与中间合金的成分及其第二相的类型有直接关系，即与不同中间合金的细化机理相关。

The Grain Refinement Mechanism of AlTiC, Al4B and Al3Ti4B Master Alloy in Pure Aluminium and Hypoeutectic Al-Si Alloys

Grain refining effects and mechanisms of AlTiC, A14B and A13Ti4B master alloy upon commercial pure aluminium and hypoeutectic AJ-Si alloys have been investigated. It is found that A16Ti0.2C master alloy have a very good refining effect upon pure aluminium but have almost no effect upon hypoeutecitic Al-Si alloy, whereas AlTiB master alloys with substoichiometric ratio(w(Ti)/w(B)<2.2) such as A14B and A13Ti4B alloys (wTi/wB=0 for A14B alloy) have no effects upon pure aluminium but have an excellent potency in refining hypoeutectic Al-Si alloys. The experimental results perhaps are attribute to different grain refining mechanisms of these master alloys in pure aluminium and hypoeutectic Al-Si alloys.